package com.lin.reggie.controller;

import com.lin.reggie.utils.R;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.lang3.StringUtils;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.UUID;

/**
 * @auther lin
 * @create 2022-05-28 10:08
 * 实现文件上传和下载
 */
@RequestMapping("/common")
@RestController
@Slf4j
public class CommonController {

    @Value("${reggie.path}")
    private String basePath;

    /*
    实现图片上传
    //参数 名字必须与前端定义的参数名一直，不能随意取
     */
    @PostMapping("/upload")
    public R<String> upload(MultipartFile file){
        //file是一个临时文件，需要转存到指定位置，否则本次请求完成后临时文件会删除
        log.info(file.toString());

        //文件名动态化
        String originalFilename = file.getOriginalFilename();
        //截取后缀
        String suffix = originalFilename.substring(originalFilename.lastIndexOf("."));
        String finalName = UUID.randomUUID().toString()+suffix;

        //判断是否存在这个目录，如果不存在需要创建出来
        File dir =new File(basePath);
        if (!dir.exists()){
            //目录不存在，需要创建
            dir.mkdir();
        }

        try {
            //临时文件转存到指定位置
            file.transferTo(new File(basePath+finalName));
        } catch (IOException e) {
            e.printStackTrace();
        }

        return R.success(finalName);

    }

    @GetMapping("/download")
    public void download(String name, HttpServletResponse response){

        //输入流，通过输入流读取文件内容
        try {
            FileInputStream fileInputStream = new FileInputStream(new File(basePath+name));
            //输出流，通过输出流写回浏览器
            ServletOutputStream outputStream = response.getOutputStream();

            response.setContentType("image/jpeg");

            int len=0;
            byte[] bytes = new byte[1024];
            //循环读取response中的输出流，
            while ((len=fileInputStream.read(bytes))!=-1){
                //开写
                outputStream.write(bytes,0,len);
                outputStream.flush();
            }
            //关闭资源
            outputStream.close();
            fileInputStream.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }


}
